Apparatus for controlling temperature and humidity.



W. TAYLOR, R. E. ATKINSON & D. M. NESBIT. APPARATUS FOR CONTROLLING TEMPERATURE AND HUMIDITY.

APPLICATION FILED 001. 23, 1908.

1,017,345, Patented Feb. 13,1912.

1 2 SHEETS-SHEET 1.

lllllllllllilllnlllllll (A W. TAYLOR, R. E. ATKINSON 6: D. M. NESB IT. APPARATUS FOR CONTROLLING TEMPERATURE AND HUMIDITY. APPLICATION FILED 0013.23, 1908.

1,017,345, Patented Feb. 13,1912.

2 SHEETS-SHEET 2.-

W/ T/VEJSE 4 i To all whom it may concern:

UNITED STATES PATENT OFFICE. WILLIAM TAYLOR, or LEIcEsTER, ROBERT ERNEST ATEINSO'N; or KNJisHToN. AND

DAVID MEIN NFsBIT, OF LEICESTER, ENGLAND.

APPARATUS FOR CONTROLLING TEMPERATURE AND HUMIDITY.

Be it known that we, WILLIAM TAYLOR, a subject of the King of Great Britain and Ireland, and residing at Abbotsbury, Upper New Walk, Leicester, in the county of Leicester, ROBERT EBNEST ATKINSON, a subject of the King of Great Britain and Ireland, and residin at Jesmond Dene, Morland avenue, Knighton', in the county of Leicester, and DAVID MEIN NEsBIT,-a subject of the King of Great Britain and Ireland, and residing at Barkby Lane, Leicester, in the county of Leicester, England,

have invented certain new and useful Improvements in Apparatus for Controlling Temperature and Humidity, of which the following is a specification.

This invention relates to apparatus such as is used for controlling the temperature or the humidity of the air in rooms, factories, trains, ships and the like, and particularly to that class of instrument by" which variations 'of temperature or' humidity causing corresponding expansion or contraction of a prime governing member are made thereby to control the supply of a fluid agent, such as air, to a motor which actuates the valves,

damper, spray, or other controlling member,

of the heating or humidifying apparatus.-

The principal object of this invention is to provide an instrument which shall control temperature or humidity within smaller limits of variation than heretofore, and shall contain parts of the simplest character not liable to derangement. I

It is usual with air-actuated motors of the kind generally employed in connection with air-controlling thermostats, to provide a weight or spring which actuates the motor one direction while the air controlled by the thermostat actuates the motor in the contrary direction; and in order that theweigh't or spring-may be free to actuate the motor when the air supply is cut ofi by thethermostat it is usual to vent the motor, which is sometimes done by providing it f 4 'witha permanent leak. Such a leak how ever,' if large, entails considerable waste of air,'and if'small is liable to become choked and inoperative by the de osit of dust.

It is a further object o this invention to provide a leak of such a character and so protected that it may be very small without becoming choked.

In air-controlling "thermostats in which to rear. -A--B of Fig. 1. Fig. 4 is .a cross section on 1 the line CD"of Fig. -1, and Fig. 5 is a Specification of Letters Patent; P t t 1 1 1 13, 1912, Application filed 0ctober 23, 1908. Serial No. 459,268. i

members are employed, it has been usual, when great sensitiveness is required, to eniploy expansion members of very considerable and often inconvenient length, or else .to employ levers or other devices to produce from the movement of a. shorter expansion member, an increased movement of the fluid-controlling valve. In addition to such magnifying levers, Bourdon tubes and other devices have been used to further increase "or to modify the sensitiveness of thermostats.

air when the valves are but slightly opened.

.Now by means of this invention we secure.

the desired sensitiveness merely by using valves and leaks of suitable character and usual magnifying levers'and other'like devices.

Our invention may be usedto control motor-actuating-fluids either in compression or tension, and 'sincein the case of a'heating system when the radiators are served with a heating medium at less than atmospheric pressure, air in tension is easily provided by plping between the radiator and the thermostat, this invention will be described and illustrated with reference especially to such a system though it is not confined to such.

In the accompanying drawings which illustrate one form of thermostat or humidostat according to the invention, Fi re 1 is 'afront elevation, and Fig. 2 a sectional elevation,the section being taken from front Fig. 3 is .a cross section on the line cross section on the line E-F of Fig. 1.-

In carrying out the invention according to one mode as inthe application to an instrument designed for attachment to a wall, 5

a base, a, of metal, or the like material which is secured to the wall by means of a detach: able lug or wall plate, I), has fixed to it, preferably by means of an exterior screw collar,

0, a. tubular expansion member, d, whose 110 for their greater rigidity solid. expansion 7 5 valve, thus obstructing the free passage of 80. proportions, and we thus dispense with the length is intended to be afiected by changes of temperature or humidity or both. As a material for the expansion member i, having a fairly high co-efiicient of temperature expansion, we prefer to use hard vulcanized rubber, and in order to enhance its heat-absorbing and radiating power and thus its responsiveness to sudden changes of temperature we use rubber with a black and dull, that is, unpolished surface. As a material for the expansion member, (Z, sensitive to changes of humidity, we prefer one which is expanded by an increase of humidity and we employ, for example a tube of gelatin which we prefer to treat as with bichromate of potash and exposure to light, so as to render it insoluble, and towhich we may add salts, glycerin, or other agent with the object of modifying its mechanical rigidity or its avidity for moisture and its sensitiveness to changes of humidity. When we wish to control the temperature of a room with reference to the humidity of its atmos 'phere, or when as in greenhouses, dwellings,

textile mills and the like, we wish to control the supply of moisture to the atmosphere with reference to the prevailing tempera ture, we construct the expansion member, (Z, as to its length, partly of material sensitive to temperature changes and partly of ma terial sensitive to changes of humidity in any required proportions. Or we may employ one material such as gelatin whose length is expanded both by heat and moisture.

Socketed in the beforementioned base, a, centrally within the tubular member, (Z, is fixed a tubular strut, e, of glass, porcelain, or the like material having a low co-etficient of temperature expansion and practically or wholly unaffected as to its length by moisture. A valve seat, 7, nearly filling the tubular expansion member, 03, preferably of a diameter as shown about one eighth of the length of the expansion member 0?, and having a sharp sloping edge, g, upon which dust cannot easily collect, is fixed upon the strut,

e, the diameter of the edge or seating, g, filling as much as possible of the diameter of the tubular expansion member, d. A

valve disk, h, whose under face is preferably a plane surface, and which we prefer to make of glass, rests upon the sharp edged seating g, and fits loosely within the expansion member all. A ring a, into which the top of the membend, is fixed, is partly threaded as at 9, to receive a cap is, capable of being turned by hand. A temperature or humidity scale, Z, is marked on the cap is, and a pointer, m, is provided on the ring, '5. A spring lock bolt, a, seated within the ring 71, engages holes in the cap, is, corresponding with the division of the scale, Z, and is released when necessary by 'a' suitable key. Adjustably fixed by a lock screw, 0, in the center of the cap, is, is a screw p, against the head of which a collar, 9, is urged bya compressed spring, 1', whose other end abuts against an inturned flange on the ring, 2'. A diaphragm, s, of corrugated metal, cellu loid, or the like, is clamped at its center to the collar, Q, by a screw stud, t, and at its periphery is clamped between the tubular expansion member, d, and the ring, 2', thereon and forms an air seal.' Suitable ports, u, o, in the base, a to which piping may be connected, communicate respectively with the bore of the tubular strut, e, and the annular space between the strut,le, and the tubular expansion member, d.

Within and beneath the base, a, so that dust will fall from it gravitationally, is a chamber, to, communicating with the tubu= lar strut, e, and in which is removably fixed, by a clamp ring, 0'0, and an elastic sealing ring, 3 a plate, a havingoin it a small pin hole 2 of about one hundredth of an inch diameter shown as about one twelve thousandth the area of the valve seat 9 such pin holes or leaks as usually constructed. with a length of-one or more diameters invariably become choked with dirt, but we chamfer the pin hole at one or both sides to a sharp edge and thus prevent the lodgment of dust therein; and to further prevent the access of dust, at filter, 3, of porous carbon or the like material is removably fixed in the chamber, by a screw cover 4 and sealed by an elastic ring, 5, the arrangement being such that air passing from the central open cavity 6 of the filter 3, through its porous walls escapes from its large exterior surface at a low velocity into the annular cavity and passes thence upward to the small pin hole 2 so that dust is not liable to be carried to and choke the pin hole.

A perforated casing 7 surrounds and protects the expansion member, at, and serves to carry an ordinary thermometer and scale 8.

In use the action of the apparatus is as follows :If, for example, it is intended to control the temperature only of the room,

in which the thermostat is fixed, by actuating the steam valve of a radiator or radiators (such a valve, for example, as is described in the specifications to Patent Nos. 869612 and 893124) the port, a, leading to the strut, e, is connected by piping to the motor chamber of the steam valve, and the other port, '0,

leading to the annular space between the strut, e, and the expansion member, at, is connected to a vacuum pump or its equivalent. If new the temperature of the room be such that the expansion member, cl, is contracted so as to release the head of the screw, 29, from the collar 9, so that the valve disk, h, is closed by the pressure of the spring, 1", acting thereon through the stud, 25, no air will be drawn past the valve disk, it, but air will be free to pass through the filter will be seen that the air from the room 3 and pin hole 2 until the pressure within.

the port at, leading to the strut e, and in the motor chamber of the steam valve, is the normal pressure of the atmosphere, and the steam valve spring or its equivalent will open the valve and admit steam to the radiators. When the-temperature of the room reaches that at which the thermostat is set,- the expansion member -03, will have expanded until the beforement-ioned stud t, is just raised from the valve disk 72,, past which air will be drawn, thereby reducing the pressure in the motor chamber of the steam valve and causing air to be drawn also through thepin hole 2. When the expansion member, 01', has expanded until the air drawn past the valve disk, It, is in excess of that leaking through the pin hole 2,

the pressure in the motor chamber of'the steam valve will gradually fall and the steam will thereby be shut off until only sufficient is supplied to maintain the required temperature of theroom. The object of the leak at 2 is to enable a balance to be established as between the action of the steam valve spring and the opposing action of the air on the motor diaphragm, thereby permitting steam to be partially turned on when so required and avoiding alternations between no steam and full steam which would otherwise be inevitable. The temperature of the room can be varied at will by turning the cap, 1:, according to the scale Z, thereon. The screw p, with its locking screw, 0, is used to adjust the instrument so that the valve disk It, acts at the temper ature indicated by the scale Z.

The sensitiveness of a thermostat of this,

character may be measured by that rise df temperature which will open the thermostat valve sufliciently to close the steam valve besides supplying the wastage of the vent orleak. It will be seen that in our form of thermostat we attain such sensitiveness by using an exceedingly small leak of only about one hundredth of an inch diameter, by employing a valve of relatively very large diameter with a plane facenormal to the direction, of expansion ofthe expansion member and co-acting with a sharp-edged valve seat of similarly large diameter, the sharp edge offering the minimum resistance to the passage of air, and the large diameter giving correspondingly large area of opening when the valve is b'ut'slightly displaced from its seat. racy are further promoted by the arrangement of the spring 1' having an abutment in the ring z' and serving to eliminate all backlash from the screw of the adjustable cap is and from between the screw p and the collar 9 so that the valve closing stud t is heldin rigid operative relation to the ringi and to its end of, the-expansion memberd. It

The sensitiveness and accuscribed.

drawn through the leak Z passes up the tubular strut e through the valve h and returns downward around the strut e and within the expansion member (Z, thus 'causture rat-her than one which thus contracts,

because thereby we are enabled readily to satisfy psychrometric conditions which demand for'any increase of humidity a certain corresponding decrease of temperature. Instruments have been proposed in which an expansion member sensitive to heat changes has been provided with a wet jacket on the principle of the wet bulb thermometer;' and woven and twisted fabrics have been employed as expansion members sen sitive to changes of humidity. In alltsuch cases however contraction instead of ex- 1 pansion occurswith any increase of humidity and therefore such members cannot be conjoined mto one w1thmembers sensitive only to heat changes to control temperature with reference to humidity or humidity with reference to' temperature psychromet-vv rically as in the presentvinvention.

4 Having now described our invention,

.what we claim as new and desire to secure by Letters Patent is 1. In a thermostat for controlling temperature with reference to humidity, a coml pound expansion member partofthe length of which is composed of a substance which expands with increase of temperature, and

partof a substance which expands with increase of humidity substantially as described. I g

2. In a thermostat for controlling temperature with reference to humidity, the

combination with a valve for controlling a motor-actuating fluid, of a compound expansion member adapted to actuate the valve and part of the length of which is composed of a substance which expands with increase of temperature, and part of a substance which expands with increase of humidity substantially as described.

3. In a humidostat for controlling humidity with reference to temperature a compound expansion member part of the length of which is composed of a substance which expands with increase of temperature, and

part of a substance which expands with increase of humidity substantially as de- 4 In a humidostat for controlling humidity with reference to temperature, the combination with a valve a motor-actuating fluid, of a compound expansion member adapted to actuate the valve and part ofthe length of which is composed of a substance which expands with increase of tempera ture, and part of a substance which expands with increase .of humidity substantially as described.

5. The combination with a controlling instrument of the kind herein referred to, comprising a tubular expansion member part of the length of which is composed of a substance which expands with increase of temperature and part of a substance which expands with increase of humidity, a relatively non-expanding tubular member in the aforesaid expansion member, a valve actuated by the expansion member and for the purpose of controlling the flow of a fluid agent acting on the expansion member and circulated longitudinally through the inner member and through the annulus between the members, substantially as described.

' 6. The combination with a controlling instrument of the kind herein referred to, comprising a tubular expansion member part of the length of which is composed of a substance which expands with increase of temperature and part of a substance which expands with increase of humidity, a second tubular member lengthwise therein, a union for the members at one end, a valve on the free end of the inner member and within the outer member, an abutment actuated' by the free end of the outer member to close the valve the aforesaid union. having ports for permitting the circulation of fluid longitudinally through the inner member, the valve, and the annulus between the members, substantially as described,

7. The combination with a controlling instrument of the kindherein referred to comprising a tubular expansion member, a second tubular member lengthwise therein, a union for the members at one end, a valve on the free end of the inner member and within the outer member, and an abutment actuated by the free end of the outer member to close the valve, said union having ports, communicating respectively with the inner member and the annulus between the members for permitting the circulationof fluid longitudinally through the inner member, the valve, and the annulus.

' 8. In a controlling instrument of the kindherein. referred to, the combination with a tubular expansion member part of the length of which is composed of a substance which expands with. increase of temperature and part of a substance which expands with increase of humidity, said expansion member forming a chamber for a fluid agent, and containing a valve for cont-rolling the fluid, a valve seat, an abutment to close the valve, and a closure for one end of the tubular member, of a flexible diaphragm to seal the other end and means therewith for adjusting the abutment relatively to the expansion member, substantially as described.

9. A controlling instrument of the kind herein referred to comprising a tubular expansion member, a second tubular member therein, a union for the members at one end, a valve on the inner member actuated directly by the expansion member and adapted to control a working fluid, a cap for the expansion member, an abutment for closing the valve, means actuated by rotation of the cap to vary the longitudinal position of the abutment, and means as at n for locking the cap in any adjusted position, substantially as described.

10. In a controlling instrument of the kind herein referred to, the combination with a tubular expansion member, means for separately permitting ingress and egress of a fluid agent to and from the tubular expansion member, a valve in-the expansion member for controlling the fluid agent, an abutment actuated by one end of the expansion member to close the valve, and means for adjusting the abutment longitudinally, of a spring permanently under stressand acting between the adjustment means and the end of the expansion member to take up backlash in said adjusting means, and to prevent damage to the instrument when the expansion member shrinks farther than is necessary to close the valve.

11. In a controlling instrument of the I kind herein referred to, the combination with a tubular linear-expansion member having means for permit-ting ingress and egress of a fluid agent to and from its interior,-of a valve actuatedby the expansion member to control the fluid agent, said valve having a substantially flat face normal to the direction of motion of the expansion member, an annular valve seat with which said valve co-acts said seat having its acting edgesharp and beveled so as to offer minimum resistance to the passage of the fluid agent and to prevent the lodgment of dust thereon, substantially as described.

12. In an instrument of the kind herein referred to for controlling a fluid agent, the combination with an expansion member and a valve-closing abutment actuated thereby, of a valve having a substantially flat face normal to the direction of motion of the abutment and co-acting with an annular valve seat'having its acting edge sharp and beveled so as to prevent the lodgment of dust thereon and to offer minimum resistance to the passage of the, fluid agent,

substantially as described.

'13. In a controlling ,instrument of the kind herein referred to, the combination with a tubular expansion member having a fluid agent to and from its interior, of a valve therein actuated by the expansion member to control the fluid agent, said valve having a substantially flat face normal to the axis of the tubular expansion member and co-acting with an annular valve seat having its acting edge sharp and beveled so having its acting edge sharp and beveled,

its circumference being not less than one-sixth the length of the expansion member substantially as described.

15. In an instrument of the kind herein referred to-for controlling a fluid agent,-

the combination with a tubular expansion.

member having entrance and exit ports for the fluid agent, of a valve therein, an abutment, to close the valve actuated by the expansion member, said valve having a substantially flat face normal to the direction of motion of the abutment, and an annular valve seat having its acting edge sharp and beveled and a, circumference not less than one-sixth the length of the expansion member substantially as described.

16. In an instrument of the kind herein referred to for controlling a fluid agent, the combination with an expansion member, a chamber for the fluid having ports for its entrance and exit respectively and an additional aperture permanently in communication with the through which the fluid can leak, of a valve actuated by the expansion member to control the fluid'agent, and an annular valve seat co-acting therewith and having an area at least 500 times that of the said aperture through which'the fluid leaks, substantially as described.

17. In an instrument of the'kind herein referred. to for controlling a fluid agent, the combination with an expansion member, forming a chamber for the fluid and a support for the expansion member having ports for the entrance and exit respectively of the fluid and an additional aperture permanently in communication with the entrance port and through which the fluid can and co-acting entrance port and leak, of a valve within the expansion memher and actuated thereby to control the fluid, and an annular valve seat co-acting with the valve and having an area atleast 500 times-that of the said aperture through which the fluid leaks substantially as described. 18. In an instrument of the kind herein referred to for controlling a fluid agent, the combination comprising an expansion member, a valve actuated thereby to control the fluid, a chamber for the fluid having ports for its entrance and exit respectively, and an additional permanent aperture through which the fluid can leak to or from the controlled side of .the instrument, the said aperture being formed by chamfering a hole to a sharp edge so as to prevent the lodgment of dust therein, substantially as described. v

19. In an instrument of the kind herein referred to 'for controlling a fluid agent, the combination comprising an expansion member, a valve actuated thereby to control the fluid, a chamber for the fluid having ports for its entrance and exit. respectively, and an additional permanent aperture through which the fluid can leak to or from the cont-rolled side of the instrument, the

said aperture being formed 1n a piece re-' movable for cleaning, and having means for holding and sealing it to the fluid chamber,

substantially as described.

20. In an instrument of the kind herein referred to for controlling a fluid agent, and comprisingan expansion member and a valve actuated thereby to control the fluid, the ,combination with a chamber for the fluid having ports'for its entrance and exit respectively and an additional permanent aperture through which the fluid can leak, of a second chamber communicating with said aperture, a removable hollow filter-for the fluid entering the aperture, the filter be ing' so arranged as to leave an annular space between itself and the chamber, and means for sealing and holding the filter removably in the chamber, substantially as described.

In testimony whereof we have signed our names to this specification in the presence of two subscribing witnesses.

Witnesses:

WALTER W. BALL, F. I-Ioon. 

